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A few Challenges in massive star evolution

A few Challenges in massive star evolution. ROTATION. MAGNETIC FIELD. MULTIPLICITY. 50-70%. 6-7%. 40%v crit. What is the origin of these distributions. How do these distributions vary with metallicity?. How do these distributions vary with the environment? (e.g. stellar density).

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A few Challenges in massive star evolution

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  1. A few Challenges in massive star evolution ROTATION MAGNETIC FIELD MULTIPLICITY 50-70% 6-7% 40%vcrit What is the origin of these distributions How do these distributions vary with metallicity? How do these distributions vary with the environment? (e.g. stellar density) What are the impacts on the interior?

  2. Rotating models With and without Dynamo. + Limongi & Chieffi 2013 13-120 Msol, solar Z No internal magnetic field + Ekström et al. (2012) No internal magnetic field + Georgy et al. (2012; 2013) No internal magnetic field

  3. Asteroseismology of red giants • Mixed modes in the redgiant KIC 7341231 (0.84 Msol, [Fe/H]=-1) • Rotationalsplittings for 18 modes (Deheuvels et al. 2012)Inversion of the rotation profile: OBSERVATION MODELS Micro Hertz Nano Hertz c = 710 ± 51 nHz (innermost 1.4% in r) Vini= 2 km s-1 ADDITIONAL MECHANISM OPERATING DURING THE HR CROSSING shellular Solid Xc=0.1 Solid Xc=0 s < 150 ± 19 nHz Deheuvels et al. 2012 Ceillier et al. 2013

  4. 3) Where are the progenitors of the luminous type IIP SN ? Upper luminosity Of SNIIP progenitors RSG≠End Point RSG=End Point Levesque et al. 2005 Tracks from Ekström et al. 2012

  5. 4) Which stars are the progenitors the type Ibc supenovae? Smartt 2009

  6. 4) Which stars are the progenitors the type Ibc supenovae? Smartt 2009

  7. Whyso few detections of type Ibcprogenitors? ~13 archives images, only one detection Pre SN are WO stars not WN or WC stars Toolow L for beingdetected Observedupperlimit Models Groh et al, A&A in press; Yoon et al. 2012

  8. THE ONLY PROGENITOR DETECTED SO FAR FOR A TYPE Ibc: iPTF13bvn Cao et al. 2013 Models Obs of iPTF13bvn Groh et al. 2013 …QUITE WELL EXPLAINED BY THEORY OF SINGLE STARS

  9. 12-22 6-12 43-62 13-22 Observed rates Eldridge et al 2013 Smith et al 2012

  10. Rotating models with no internal magnetic field WR Pre SN Zsol Woosley 2003 For NS at break-up For NS with P=20mms

  11. DO MASSIVE STARS ROTATE LIKE SOLID BODIES ON THE MS? MAGNETIC FIELDS MAY ACTUALLY BE INVOLVED IN A DIFFERENT WAY MAGNETIC BRAKING AT THE SURFACE MAGNETIC BRAKING OF THE STELLAR CORES LONG GRB MAY THEN OCCUR IN SITUATIONS WHERE THESE MAGNETIC BRAKING PROCESSES ARE NOT PRESENT FAST ROTATORS AVOIDING THE RED SUPERGIANT PHASE?

  12. HOW A RSG ROTATE IN THE INTERIOR? (SHELLULAR MODEL, NO MAGNETIC FIELD, SOLID BODY ROTATION IN CC)? 15 Msun, Z=0.014, Vini/Vcrit=0.4 Surface velocity is 0.04 km s-1 critical velocity At the surface is About 16 km s-1 Mr/Msun A SMALL FAST SPINNING CORE IMMERGED IN A SLOWLY ROTATING ENVELOPE Pulsar rotation estimated from conservation of angular momentum in the central 2 Msun:  9.2e-5 s, a period 217 times smaller than 20 ms TOTAL ANGULAR MOMENTUM:  (1050 cm2g-1) 12.0 ANGULAR MOMENTUM IN THE ENVELOPE: 4.3 ANGULAR MOMENTUM IN THE CORE:  1.0 If envelope absorb Lcore increase of only 23% of the surface velocity A COUPLING EFFICIENT ENOUGH BETWEEN THE CORE AND THE ENVELOPE WOULD HAVE A STRONG IMPACT ON THE ANGULAR MOMENTUM OF THE CORE WITHOUT CHANGING TO MUCH THE ANGULAR MOMENTUM OF THE ENVELOPE

  13. THE DIFFICULTY HOW TO RECONCILE THE LOSS OF LARGE AMOUNT OF MASS (H-RICH ENVELOPE REMOVED) WITH FAST ROTATING CORE? POSSIBLE SOLUTIONS STARS BECOME H-POOR BY EVOLVING HOMOGENEOUSLY THE ANGULAR MOMENTUM TRANSPORT BETWEEN CORE AND ENVELOPE REMAINS MODEST AT EVERY TIME PREDICTIONS AND IMPLICATIONS ARE DIFFERENT HOMOGENEOUS EVOLUTION DIFFERENTIAL ROTATION Yoon et al. 2006 (interior magnetic field) Hirschi et al. 2005; Georgy et al. 2009, 2012 (No interior magnetic fields) Only very fast rotators at low Z Moderate rotators and Ic only when (C+O >He) GRB/CC ~ 2% at Z=0.002, 5% at Z=0.00001 GRB/CC ~ 7% at Z=0.004, 0.008 WEAK WR WINDS AT LOW Z NEEDED Moderately rotating stars are also solid body rotating on MS  Rotation of pulsars need braking mechanisms to explain rotation of pulsars Asteroseismology? Core braking mechanism?

  14. Shellular rotation Roche approximation MOST OF MASS SPHERICAL DISTRIBUTION EQUATIONS FOR MEAN VALUES ON ISOBARS ON ISOBARS DIFFERENCE WITH RESPECT TO MEAN VALUES SMALL (LEGENDRE) 1.5D

  15. Numerical treatment of the meridional circulation • Treatment of the ``mixing blocking effect’’ of mu-gradients • Choice of the diffusion coefficient • Inclusion of a dynamo in radiative zone • Inclusion of internal waves • Inclusion of anisotropic winds • Inclusion of magnetic braking by the winds

  16. Massive star evolution (at solar Z, above 30 M ) OB-type LBV WR SN Ibc or BH ☉ 85M So far, no observations of WRs as SN progenitors (Smartt 09) Wolf-Rayet OB-type LBV ☉ (after evol. tracks from Meynet & Maeder 03, Ekstrom+ 12)

  17. 5) ROTATION AND PROGENITORS OF LONG SOFTGAMMA RAY BURSTS

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